Turbocharger



Feb. 2, 1954 Filed Nov. 8, 1949 A. J. LARRECQ TURBOCHARGER 5 Sheets-Sheet 1 INVENTOR ANTHONY J. LARRECQ AT ORNEY A. J. LARRECQ Feb. 2, 1954 TURBOCHARGER 5 Sheets-Sheet 2 w MM. E R M n O m M. m km w J u 0 N V Mb N H mm W N HEN; .fikmfikwutki A Y Q VQN. 8 m Mn. NW 92. I, mm y v 8 90 um QM .Nm. 7 NW Q n. J J X\\\ y 8. av Q Q. R w mm. m Nb Mb In? n m Nu N x Mm Nov SN I I l I I l I I I I I I I J I I I l mu! m AN .3 8 &N| mm 3 8 8w mm m 3 R\ 8 WW QMW W NNN.

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TURBOCHARGER 5 Sheets-Sheet 3 Filed NOV. 8, 1949 INVENTOR ANTHONY J- LAPRECO ATTORNEY A. J. LARRECQ Feb. 2, 1954 TURBOCHARGER 5 Sheets-Sheet 4 Filed Nov. 8, 1949 INVENTOR ANTHONY J. LARRECO V A TTORNE) Feb 2,1954i A. J. LARRECQ 2,668,006

TURBOCHARGER w Filed Nov. 8, 1949 I 5 Sheqts-Shet 5 INVENTOR ANTHONY J. LARRECO BY- l Patented Feb. 2, 1954 UNITED STATES 'CiF'fFl' CEv TURBOCHARGER' Anthony J; Larrecq, Yardley, re assignor to Baldwin-Lima-Hamilton Corrmration;v a compo ration ofPennsylvania Application November 8, 1940, Serial No. 126,109

This invention relates generally to turbochargers and more particularly.- to an improved type of internal combustion engineexhaust gas turbine driven turbocharger wherein a-multiplicity of engine exhaust manifolds are employed, each manifold communicating with individual nozzle segmentswhich .in turn cooperate withan elastic fluid turbine designed.- tocconvert the. kinetic energies of the combustion turbine exhaust gases to mechanical work required for driving an air compressor.

An object of the invention.- is to provide a turbocharger of the: type: described havingan improved relationship of the turbine, compressor and supporting shaft elements, whereby the stresses occurring-in the turbine wheel are minimized without compromising the ability; oi the turbine wheel. to efficiently absorb. the. kinetic energy imparted by-the. engine: exhaust gases under the conditions.oi. pressure fluctuation existing in the separately divided= multiple'engine exhaust manifolds.-

Anotherobject isto provide a turbocharger oi:

the type described hailing all-improved" relationship of the turbine, compressor; 7 anci supper-ting,

shaft elements, whereby the turbine and com pressor elements can be-outboarchof the shaft supporting bearings contained in a; common structure wherein: the bearing alignment-is unaiiected by disassemblya" M A further object is to provide. a turbocharger.

of the type described-having amimproved rela-- tion of turbine wheel and cooperating nozzle trio-g wherein the latter canbereadiiy? replaced to accommodate the varying: conditions or .internal combustion engine exhaustgas: pressure fluctuations. v g

A still further object istoprovidea turbocharger of thetype described havinganimproved combination employing an. enclosure. for the nozzle ring support with sealing connections thereto of-such construction. as toefiectively, prevent the egress of high pressureiexhaustlgases.

into the enclosure. which receives I the. exhaust gases from. the turbine wheel;

Another object is to-providea turbocharger of the type described having.anmimprovedcombinaa tionof labyrinth chambers cooperatingiwith the turbine wheel andtherearpart of. anfenclosure for receiving gases. discharged from the. turbine oil vapor.

9 Claims. (or. 230-116) A further objectis to provide a turbocharger of the type described having a rotating impeller with entryvanesintegral with alternate discharge vanes; said'entry vanes" cooperating with an integrally cast shroudpermitting multiple sealson the periphery thereof, to the end 'of wheel,- the compressor impeller; and the support-- I ing-shaft;

Fig; 3 is'a partial; enlarged-'endview-of the turbine wheel I Fig. 4 is an elevational view ofone of the turbine blades;

Figs. 5, -6--and' '7 are cross-sectional views'of a turbine blade showing the varying contours thereof, taken along the lines- 55, 3-6; and 1-1 respectively of Fig.4";

Fig. 8 is a partial, enlarged enclview of the compressor impeller;

Fig. 9 isanenlarged sectional elevationoithe compressor impeller; showing the impeller sleeve; 4

Fig. 10 is a perspective of the-turbinewheel;-

and i Fig. 11 is a diagrammatic view of the-vanes of, the compressor impeller; taken along the line In the particular mbodimentof the invention which is; disclose'd herein :merely for the purpose of illustrating one specific form among'possible others that the invention might take in practice,

I show inFi'gst l and 2, in compact arrangement;

tained ina common bearingsupporthousing;.,2-l which itself. includes a turbine exhaust chamber" back-plate y2la=connectirigswith a turbine exhaust chamber: 2-8; Fig; l,- envelopinga nozzle support Bearing; housing 23 supports: a: compressor collector chambers] cooperating with: a support plate 33 to-whichis attached'a difiuser 34 and anair filter 3 l Reierrina more particle.- larlyr to..Figs: .3.-andalll, turbine wheelii coma prises a multiplicityof passages. 16- boundedron two sides by varieslifprojectihg from aoentral housing 2,9

hub M which constitutes th thirdside of the vane passage. The remaining or fourth side of the multiple vane passages is defined by an outer contour I3 of the vanes, which outer contour I3 itself conforms to the shape of a cooperating adjacent stationary shroud 23a, Figs. 1 and 2, which is a part of nozzle ring support 29. The surfaces of vanes I5, Figs. 3 and 10, are warped with respect to radial planes II and Ila, passing through turbine axis I and planes transverse thereto. At any transverse plane 9a, Fig. 2, the vane surfaces are defined by contour shapes Ia and lb, Figs. 5 to 7, wherein it will be seen that the thickness of the vane progressively increases towards the root thereof. The surfaces of vanes I5 are so warped as to permit entry. without shock into vane passages I6 of the exhaust gases discharged from a nozzle ring32, Fig. 2. Vane passages I6 are also so warped as to permit'egress of exhaust gases in substantially axial direction relative to nozzle support housing 29. The degree to which the vane surfaces are warped is limited by the permissible vane root stress which i adversely affected by a combination of centrifugal and bending stress arising from the displacement of vane section centroids 6a and 617, Fig. 6, relative to radial planes II and Ila passing through turbine axis I0. The greater the degree of warping in vane passages It, the greater will be the energy absorbing capacity of a turbine wheel for a given peripheral velocity. The optimum degree of vane warping depends upon the interrelationship of turbine wheel axial depth X, Fig. l, and the turbine wheel diameters Y and Z. Turbine shaft lengths are U and V and turbine shaft diameters W and W. For internal combustion engines having four (4) exhaust manifolds, the optimum combination of these parameters lies within the approximate limits defined by the following table, it being understood that while the figures of this table and of other values appearing elsewhere herein are carried to the third decimal point, yet this is merely by way of illustration of one specific example and variations thereof may be made within the scope Compressor impeller 49, Figs. 1, 2, 8, 9 and 11, comprises a multiplicity of passages 51 bounded at inlet 53 by surfaces 59a and 59b of vanes 56, Figs. 8 and 11, bounded by hub contour 60, Figs. 2 and 9, and bounded-by shroud contour GI. Multiple impeller passages 54 and 55 are continuations of passages 5i and joining the latter at a distance 0, Fig. 1, beyond inlet 53, extending to the periphery of rotating impeller 49, conforming to cooperating contour 62, Fig. 2, of impeller inlet housing 33. Thus impeller passages 54 and 55 are divided by a partition 51, Figs. 8 and 11, which extends from a point where the passages meet to the periphery of rotating impeller 49. The centroid of impeller vane sections 59a and 5% at a distance'beyond dimension 0 from the inlet lie substantially in a common radial plane relative to the impeller axis. The centroid of vane surfaces 590, and 59b in the section defined by dimension 0 lie substantially in parallel radial planes passing through the impeller axis. The necessary degree of warping of the vane passage relative to the radial plane passing through the discharge of vanes 55 depends upon the rela- Upper Limit Lower Limit A shroud 64, Fig. 2, provided at the inlet periphery of impeller 49 effectively eliminates vibration induced by the impingement of air upon inlet edges of the impeller vanes and also permits removal of metal for balancing purposes and also permits use of a labyrinth 83 to minimize air leakages. Impeller 49 is further provided with excess metal at point 65 for balancing, said balancing being furtherfacilitated by provision of sleeve 66 as a permanent sub-assembly, shrunk therein and held in relative angular position by means of splines 61. The provision of sleeve 65 permits the use of lightweight metals for impeller 49 without comprising the possibility of actual interchangeable fitting on shaft 2|. Impeller sleeve 66 is so formed as to permit absorption of angular torques by pins 68 and which effectively transmit torque from shaft 2I, said pins being held in position by prongs l3 and 'II on sleeve 65, prongs I2 on shaft 2!, and by enclosing surfaces 13 and I4 of nut F5. The axial position of impeller sleeve 66 and therefore the axial position of impeller 59 is determined by the abutment of sleeve surface 16 against surface 11 of a thrust collar I8 which itself butts against shaft surface I9. The angular relationship of thrust collar 78 and impeller sleeve 66is determined by pin 69. Interspersed between thrust collar I8 and impeller 49 is a labyrinth seal 80 which is itself readily removable from sleeve 66 by virtue of an indexing spline and radial positioning pilot 8 I The material for labyrinth seal 80 can differ from that of impeller 49 and impeller sleeve 66. The material of thrust collar I8 should preferably be the same as impeller sleeve 66 and shaft 2| and all of which should be subject to hardening by heat treatment.

Referring more particularly to Fig. 2, it will be seen that turbine shaft 2| is attached to turbine wheel H by means of a weld 82, the separation therefor being such as to provide heat dam, comprising a pilot 84, an abutment 85, and an air gap 86. Before said heat dam is supplemented by cooling air holes 89 communicating with a chamher 8'! and a chamber 88, the latter chamber communicating with a chamber 90 at which point pressur is less than in chamber 88.

Impeller shaft nut I5 can be provided with a tachometer extension connection 9i cooperating with a tachometer shaft to permit registering the speed of shaft 2|.

Shaft 2! is supported in journal bearing 23 and thrust bearing 24, each of which is supported in common bearing housing 21. Oil is supplied to journal bearing 23 from annular groove 92 and bearing housing 21; said annular groove 92 being supplied by any suitable external source which also supplies a channel communicating with an annular groove 93 communicating with journal thrust bearings 25 and 26. Oil discharged from journal bearing 23 is collected in part in a chamber 94 and in part in a chamber 96. Oil col lected in chamber 94 is allowed to pass to aeeaoos;

chamber 95: at! the bottom of: the former; the collected oil is thereupon allowed to collectinia chamber 95; from, whence it is; drained through an opening 91; Oil dischargedifrom thrust bearings 25 and 26 is collected either in chamber 95 or a chamber 98, all oil collectedin the latter being eventually drained tothe former chamber through a channel I04. The diameter-of journal bearing 23 is such as to permit the removal of shaft 2! after removal of shaftnut. 15 and impeller assembly and impeller sleeve assembly 49 to 66, seal 80 and thrust-collar 18; the latter being disassembled only after-removal of an impeller carbon seal 99 and impeller oilseal. I98.

The egress of oil vapor from bearing housing 22', Fig. 2, is eliminated by the provision of impeller oil seal I 90 which comprises thread elements Hill and labyrinth elements I02. Impeller oil seal lfieialso containschannel I03. which collects oil dripping from the walls of bearing chamber 93, thus effectively preventing said: oil falling upon thrust collar 18. Impeller seal I also is provided with chamber 98 which'communicates with the bottom side of the channel I015 to deliver oil liquid to bearing housing 21. Thrust collar I8 is provided with a slinger tominimize the possibility of oil flowing along surface I05. Any oil lodged on said surface iseffectively wiped by thread elements IBI and any residual adhering oil iseffectively thrown off into a chamber I06 by a groove I01.

lhe entire exhaust gas turbine driven turbocharger assembly is supported by a base 28a, Fig. 1, of water-cooled exhaust housing 28. The subassembly shown by Fig. l mounts to water-cooled exhaust housing 2'8by'means of a'bolting flange I98 which is integral with water-cooled'backplate 210; of bearing housing 21. Nozzle support chamber 29 is itself supported in water-cooled exhaust chamber 28 by means of radial pins I09 extending from water-cooled exhaust housing 28 inwardly and cooperating with radial sockets in exhaust housing 29, all lying in a plane parallel and adjacent to aforesaid bolting flange I08.

Water-cooled exhaust housing 28 is provided with interstices 23'?) wherein the water is allowed to circulate by thermosyphon action, and to which cooling water is admitted to a lower inletflange lit and emittedat an upper outlet flange Ill. The exhaust gases discharged from exhaust housingiii pass through opening H2 provided with a flange I it to which a pipe connection can be made. Water-cooled exhaust housing 28 is also provided with a support face I I4 containing multiple radial pins H5 extending inwardly and cooperating with radial sockets in an exhaust housing end plate H6.

Exhaust housing end plate I I6 cooperates with water-cooled exhaust housing 28 to contain the exhaust gases discharged from turbine element I'i. Exhaust housing end plate I I6 also helps to support nozzle support housing 29 by means of a central extension IE6 axially slidable in a bore of the wall. Also, this supporting action is eifected by bored axial sockets I I! in which piston ring seals H8 are contained to further retain exhaust gases emitted from turbine element I7, regardless of differential thermal expansions between nozzle support chamber 29 and watercooled exhaust housing 28. The particular combination disclosed herein, Fig. 1, of the exhaust housing 23, with its radial outlet II2, enclosing the axially extending inlet pipes I I8 and the axial turbine discharge, produces a gas flow path indicated by dotted line II8a which crosses itself; thus effectingia partialfheat're covery operation, as well compact unit.

Nozzle support housing 29is thermo-elastically supported, as already described, by. radial pins I09 disposed in radial holes I24adjacent' to bolt ing flange I68 and also bybored axial: sockets Ill in exhaust housing end, plate H6. Each of the multiple chambers defined in Fig. 1, which comprise nozzle support housing 29', .are separated at the point of exhaust gas entry in exhaust housing end plate Iliiand are joined at.

the other extremity to form a, continuous periph at surface I22 when the combination of nozzlering 32, nozzle support housing 2%! and Watercooled exhaust housing 28 are bolted to watercooled back plate 21a of bearing support housing 2?. Gas leakage sealing strip I23 is made effec tive only when the aforesaid assembly is ineifect.

From the disclosure herein, it is seen that I have provided a turbochargernhavinga highly eifective' relationship ofJ-turbine, compressor and supporting shaft elements whereby the turbine isadapted to absorb efficiently the-kinetic energy of the exhaust: gases while maintaining the stressesat a minimum in the various critical parts. 'In' addition, my improved; turbocharger;

allows the nozzle ring to be easily and-readilyremoved :in a radial inlet type of turbine and at the same timeinsure maximum effectiveness against leakage of gas and oil 'vaporf'or dangerousmixing thereof. v f

It will,- of course, be understood by those'skilled in. the, art'that Various changes maybe made in the construction and'arrangement of parts withoutdeparting from thenspiritof the invention 'as set forth in the appended'claims.

I claim: v

1. A turbocharger comprising; in combination; a turbine wheel having rear and front sides with radial inlet blades on the front side, ashaft for rotatably supporting said wheel; a compressor" impeller mounted onsaid shaft; a nozzle 7 ring housing radially surrounding said turbine wheel for supplying gas thereto, a nozzle ring disposed radially adjacent to the turbine inlets and having axially extending nozzle vanes and annular members connected to the ends thereof, means for supporting said nozzle ring by said housing, an enclosure for the nozzle ring housing, said enclosure having a rear part adjacent to the rear side of the turbine wheel and a forward part adjacent to the front part of the turbine wheel and communicating with the discharge end of the turbine wheel to receive gas discharged therefrom, and annular sealing means interposed between the rear part of said enclosure and the nozzle ring to prevent the egress of high pressure gases from the nozzle ring into said enclosure.

2. A turbocharger comprising, in combination, a turbine wheel having a hub with a substantially radially extending back side and a front side with blades curved to axially discharge. the issuing gases and an inlet to receive gasses in a substantially radial direction, means providing four inletsfor supplying gas to the turbine wheel.

as providing a, very a shaft fo'r'rotatably supporting said'turbine wheel, a compressor impeller provided with a hub having an air flow deflecting surface turning the incoming air from an axial direction at its tip inlet near the hub axis to a radial direction at its discharge end and impeller vanes having a portion lying substantially in a meridian plane containing the impeller axis and another portion warped relatively to such plane, shaft bear-.

ings respectively adjacent to the turbine wheel and to the impeller, said wheel and shaft being so proportioned that with the maximum diameter of the turbine wheel considered as unity the axial length of the wheel is between 291-388 of unity, the outer diameter of the turbine wheel at its discharge end is between .814.763 of unity, the distance from the back face of the turbine wheel to the center of the shaft bearing adjacent the turbine wheel is between 214-200 of unity, the distance between the centers of said bearings is between 560-525 of, unity, and the diameter of the shaft adjacent the turbine bearing is between .200-219 of unity.

3. The combination set forth in claim 2 further characterized in that the impeller hub at its tip inlet end has a diameter between 254-238 of unity and the maximum diameter of the impeller blades at their inlet ends is 627-538 of unity.

4. A turbocharger comprising, in combination, a turbine wheel, a shaft rotatably supporting said wheel, a nozzle ring housing radially surrounding said turbine wheel for supplying gas thereto, an exhaust housing enclosing said nozzle ring housing, and means for thermo-elastically radially supporting said ring housing b said exhaust housing.

5. The combination set forth in claim 4 further characterized in that the thermo-elastic means comprises pins supported in the exhaust housing and extending radially to the ring housing.

.6. The combination set forth in claim 4 further characterized in that said exhaust housing has an end wall, and means for axially movably supporting the nozzle ring housing substantially at the center of said wall. I

7. The combination set forth in claim .4 further characterized in that the nozzle ring housing includes a plurality of inlet pipes initially extending in an axial direction and curving radially inward to the nozzle ring, an end Wall for the exhaust housing, and means for slidably supporting the axial portion 'of said inlet pipes by said end wall.

8. A turbocharger comprising, in combination, a bearing housing, a shaft journalled therein, a turbine wheel mounted on one end of said shaft, a nozzle ring housing surrounding said turbine wheel for supplying gas thereto, an exhaust housing enclosing said nozzle ring housing, and means for removably axially supporting said exhaust housing by said bearing housing whereby upon removal of said exhaust and nozzle ring housings the turbine wheel is axially removable.

9. A turbocharger comprising, in combination, a turbine wheel having a radial inlet and axial discharge, a shaft rotatably supporting said wheel, a'nozzle ring for supplying gas radially inward through said inlet, a plurality of inlet pipes connected to said ring, the initial portion of said pipes extending in an axial direction relative to the shaft axis so that the gases supplied to and discharged from the turbine flow in directions toward each other, and an exhaust housing enclosing said inlet pipes and having a radial outlet, whereby gases flow axially toward the turbine wheel and thence radially inwardly thereof to be discharged therefrom i an axial direction toward the initial axial portion of the pipes and thence radial outward from the exhaust housing.

ANTHONY J. LARRECQ.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,692,537 Baumann Nov. 20, 1928 1,959,703 Birmann May 22, 1934 2,184,197 Sohutte Dec. 19, 1939 2,296,701 Butler et al Sept. 22, 1942 2,406,388 Larrecq Aug. 27, 1946 2,445,661 Constant July 20, 1948 2,447,292 Van Acker Aug. 17, 1948 2,463,976 Kilchenmann Mar. 8, 1949 2,475,151 Nichols July 5, 1949 2,486,731 Buchi Nov. 1, 1949 2,492,672 Wood Dec. 27, 1949 2,516,066 McLeod July 18, 1950 2,556,020 Williams June 5, 1951 2,577,179 Buchi Dec, 4, 1951 FOREIGN PATENTS Number Country Date 589,689 Great Britain June 26, 1947 

